In the prior art, document U.S. Pat. No. 3,559,701 is already known that describes a refillable dispenser comprising: a reservoir; a filling valve that is mounted in the bottom wall of the reservoir; a dispenser member in the form of a valve; a pusher that is mounted on the dispenser valve; and a vent channel that extends along the reservoir from the bottom wall into the proximity of the neck. When the fluid is injected into the reservoir through the filling valve forced into its open state, the air contained in the reservoir may be evacuated through the vent channel. In that prior-art document, the vent channel is in the form of a fine tube that is mounted on the bottom wall of the reservoir and that extends freely inside the reservoir. It can easily be understood that that vent-channel design is difficult to implement at relatively low cost. It should be observed that that document is more than forty years old.
Document GB 2 229 380 is also known that describes a refillable dispenser comprising a reservoir, a pump, a pusher, and a vent channel that is made integrally with the reservoir. The refillable dispenser does not include a genuine filling valve: instead, a cone defining a small passage makes it possible to receive the actuator rod of a pump of a source bottle. Fluid may thus be injected into the reservoir, and the air contained in the reservoir may escape through the vent channel. The refillable dispenser also includes a removable cap that can be fitted to the bottom wall of the reservoir in such a manner as to close both the cone and the outlet of the vent channel. In this respect, the design of the vent channel that is incorporated in the reservoir cannot be provided in industrial manner and at moderate cost. The vent channel is shown with a section that is constant over its entire length, which would signify that it has been made by means of a fine pin of section that is constant, which is not possible in practice. Such a pin could not be removed from the channel after molding as a result of its long length and its extreme fineness.